SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ebcc562f3380a32f171eb43a9e845cc1384c847398ec16a8e8b172b7e529e8a' 
  AND token = 'OYdcvmr71v4pZdMV9ga8h0rwVL3ZtPgqBVRXU6ROJzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}